Poly(amide-imide)s Containing Polybutadiene Blocks

2000 ◽  
Vol 65 (3) ◽  
pp. 361-370 ◽  
Author(s):  
Miroslav Marek ◽  
Drahomíra Hlavatá ◽  
Jana Kovářová ◽  
Miloslav Sufčák ◽  
Jindřich Pytela
Keyword(s):  
Weight Loss ◽  
Glass Transition ◽  
Phenyl Isocyanate ◽  
Spectroscopic Methods ◽  
Wide Angle ◽  
Ordered Structure ◽  
X Ray Diffraction ◽  
Amorphous Halo ◽  
Trimellitic Anhydride ◽  
X Ray

Poly(amide-imide)s containing polybutadiene blocks were prepared by reaction of 4,4'-methylenedi(phenyl isocyanate) with trimellitic anhydride and α,ω-diisocyanatopolybutadiene. The polymers were characterized by spectroscopic methods and X-ray diffraction. Incorporation of 5 wt.% of polybutadiene structures into polyimide decreases the temperature of 10% weight loss in nitrogen by 90 °C. Glass transition temperature of the polymer also decreases with the increasing content of soft polybutadiene segments, but the decrease is moderate for the contents higher than 20 wt.%. Broad amorphous halo dominates wide-angle X-ray diffractograms of all the samples, but sharper peaks of a more ordered structure were observed in definite concentration range of polybutadiene blocks. The copolymers are soluble in N-methylpyrrolidone.

Bis(μ-carboxylato)dienerhodium(I) Complexes - Synthesis, Characterization and Catalytic Activity

2008 ◽  
Vol 73 (8-9) ◽  
pp. 1205-1221 ◽  
Author(s):  
Jiří Zedník ◽  
Jan Sedláček ◽  
Jan Svoboda ◽  
Jiří Vohlídal ◽  
Dmitrij Bondarev ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Diffraction Analysis ◽  
Spectroscopic Methods ◽  
X Ray Diffraction ◽  
X Ray

Dinuclear rhodium(I) η2:η2-cycloocta-1,5-diene (series a) and η2:η2-norborna-2,5-diene (series b) complexes with μ-RCOO- ligands, where R is linear C21H43 (complexes 1a, 1b), CH2CMe3 (2a, 2b), 1-adamantyl (3a, 3b) and benzyl (4a, 4b), have been prepared and characterized by spectroscopic methods. Structures of complexes 2b, 3a and 4a were determined by X-ray diffraction analysis. Complexes prepared show low to moderate catalytic activity in polymerization of phenylacetylene in THF giving high-cis-transoid polymers, but they show only oligomerization activity in dichloromethane.

scholarly journals New Haloterpenes from the Marine Red Alga Laurencia papillosa: Structure Elucidation and Biological Activity

Marine Drugs ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 35
Author(s):  
Mohamed Shaaban ◽  
Ghada S. E. Abou-El-Wafa ◽  
Christopher Golz ◽  
Hartmut Laatsch
Keyword(s):  
Biological Activity ◽  
Crude Extract ◽  
Structure Elucidation ◽  
Antimicrobial Activities ◽  
Red Alga ◽  
Spectroscopic Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Structures ◽  
Terpene Derivatives

Analysis of the air-dried marine red alga Laurencia papillosa, collected near Ras-Bakr at the Suez gulf (Red Sea) in Egypt delivered five new halogenated terpene derivatives: aplysiolic acid (1), 7-acetyl-aplysiol (2), aplysiol-7-one (3), 11,14-dihydroaplysia-5,11,14,15-tetrol (5a), and a new maneonene derivative 6, named 5-epi-maneolactone. The chemical structures of these metabolites were characterized employing spectroscopic methods, and the relative and absolute configurations were determined by comparison of experimental and ab initio-calculated NMR, NOE, ECD, and ORD data, and by X-ray diffraction of 2 and 6. The antimicrobial activities of the crude extract and compounds 1–3, 5a and 6 were studied.

scholarly journals Structures, Chemical Conversions, and Cytotoxicity of Tricholopardins C and D, Two Tricholoma Triterpenoids from the Wild Mushroom Tricholoma pardinum

2021 ◽  
Author(s):  
Chen Shi ◽  
Yue-Ling Peng ◽  
Juan He ◽  
Zheng-Hui Li ◽  
Ji-Kai Liu ◽  
...  
Keyword(s):  
Hela Cell ◽  
Single Crystal ◽  
Cell Lines ◽  
Cell Apoptosis ◽  
Spectroscopic Methods ◽  
Wild Mushroom ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hela Cell Lines ◽  
Mcf 7

AbstractTwo undescribed Tricholoma triterpenoids, namely tricholopardins C (1) and D (2), were isolated from the wild mushroom Tricholoma pardinum. Their structures with absolute configurations were elucidated by spectroscopic methods, as well as the single crystal X-ray diffraction. Compounds 1 and 2 were further obtained by chemical conversions from the known analogues. Compound 1 showed significant cytotoxicity to MCF-7 and Hela cell lines with IC50 values of 4.7 μM and 9.7 μM, respectively. Its mechanism of inducing MCF-7 cell apoptosis was studied briefly. Graphical Abstract

A quantitative differentiation method for plastic bags by wide angle X-ray diffraction for tracing the source of illegal drugs

2007 ◽  
Vol 168 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Valerio Causin ◽  
Carla Marega ◽  
Pietro Carresi ◽  
Sergio Schiavone ◽  
Antonio Marigo
Keyword(s):  
Illegal Drugs ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Differentiation Method ◽  
Plastic Bags

Wide angle X-ray diffraction study of the solid-phase chlorinated poly(ethylene)

Polymer ◽  
2004 ◽  
Vol 45 (18) ◽  
pp. 6341-6348 ◽  
Author(s):  
S. Stoeva ◽  
A. Popov ◽  
R. Rodriguez
Keyword(s):  
Diffraction Study ◽  
Solid Phase ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Poly Ethylene

Time-resolved isothermal crystallization of absorbable PGA-co-PLA copolymer by synchrotron small-angle X-ray scattering and wide-angle X-ray diffraction

Polymer ◽  
2001 ◽  
Vol 42 (21) ◽  
pp. 8965-8973 ◽  
Author(s):  
Zhi-Gang Wang ◽  
Xuehui Wang ◽  
Benjamin S. Hsiao ◽  
Saša Andjelić ◽  
Dennis Jamiolkowski ◽  
...  
Keyword(s):  
Small Angle ◽  
Isothermal Crystallization ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

In situ time resolved wide angle X-ray diffraction study of nanotube carpet growth: Nature of catalyst particles and progressive nanotube alignment

Carbon ◽  
2015 ◽  
Vol 87 ◽  
pp. 246-256 ◽  
Author(s):  
Périne Landois ◽  
Mathieu Pinault ◽  
Stéphan Rouzière ◽  
Dominique Porterat ◽  
Cristian Mocuta ◽  
...  
Keyword(s):  
Diffraction Study ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray

scholarly journals c-Perpendicular Orientation of Poly(ʟ-lactide) Films

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1572
Author(s):  
Baku Nagendra ◽  
Paola Rizzo ◽  
Christophe Daniel ◽  
Lucia Baldino ◽  
Gaetano Guerra
Keyword(s):  
Low Temperature ◽  
Film Plane ◽  
Wide Angle ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Amorphous Films ◽  
High Transparency ◽  
X Ray ◽  
Crystalline Forms ◽  
Induced Crystallization

Poly(ʟ-lactide) (PLLA) films, even of high thickness, exhibiting co-crystalline and crystalline α phases with their chain axes preferentially perpendicular to the film plane (c⊥ orientation) have been obtained. This c⊥ orientation, unprecedented for PLLA films, can be achieved by the crystallization of amorphous films as induced by low-temperature sorption of molecules being suitable as guests of PLLA co-crystalline forms, such as N,N-dimethylformamide, cyclopentanone or 1,3-dioxolane. This kind of orientation is shown and quantified by two-dimensional wide-angle X-ray diffraction (2D-WAXD) patterns, as taken with the X-ray beam parallel to the film plane (EDGE patterns), which present all the hk0 arcs centered on the meridian. PLLA α-form films, as obtained by low-temperature guest-induced crystallization, also exhibit high transparency, being not far from those of the starting amorphous films.

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